The present invention relates to electronic shelf label (ESL) systems or electronic signage, and more specifically to an electronic shelf label.
ESL systems typically include a plurality of ESLs for each merchandise item in a store. ESLs display the price of corresponding merchandise items on store shelves and are typically attached to a rail along the leading edge of the shelves. A store may contain thousands of ESLs to display the prices of the merchandise items.
One type of ESL is disclosed in commonly assigned to U.S. Pat. No. 5,510,602. This type of ESL takes advantage of modulated backscatter communication techniques disclosed in commonly assigned U.S. Pat. No. 5,640,683. These patents are hereby incorporated by reference.
ESLs may be required to display information in many retail environments, including coolers and freezers where specially coated glass doors can reduce signal strength from wireless ESLs. Communication difficulties often require additional RF communication equipment to be installed to compensate for the loss. For example, in the system disclosed in the referenced U.S. Patent, a communication base station (CBS) must be dedicated and in close proximity to a cooler or freezer in order to communicate with ESLs in that cooler or freezer. In addition, noise generated by devices or reflected from devices can severely impact the ability of a CBS to receive a response (acknowledgement) from the ESL following successful execution of a command by the ESL.
Therefore, it would be desirable to provide an ESL with enhanced communication capability to avoid installation of the additional RF communication equipment, such as CBSs and antennae.